Question

A coin is tossed thrice
1)find probability of getting at most three tails.

Answer 1

S={H H H
H H T
H T H
H T T
T H H
T H T
T T H
T T T}
n(S)=8

SO A{TTT,TTH,THT,HTT,HHT,HTH,THH}
n(A)=7
P(A)=n(A)/n(S)
=7/8

Answer 2

All possible events=hhh,ttt,hht,thh,hth,tht,tth,htt
No. Of possible events=8
Favourable events=ttt,hht,thh,hth,tht,tth,htt
No. Of favourable events=7
P(E)=7/8